US3605313A

US3605313A - Choke means

Info

Publication number: US3605313A
Application number: US797149A
Authority: US
Inventors: Jeremiah J Kranz
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-02-06
Filing date: 1969-02-06
Publication date: 1971-09-20
Anticipated expiration: 1988-09-20
Also published as: CA924145A

Abstract

A TUBULAR MEMBER COAXIALLY FITTED OVER THERE MUZZLE AND A SLOTTED PORTION OF A GUN BARREL IN LONGITUDINALLY SLIDING ENGAGEMENT THEREWITH HAVING AN ARCUATELY CONVERGING INNER SURFACE FOR FORCING THE SLOTTED PORTIONS OF THE GUN BARREL INWARDLY TO VARY THE CHOKE THEREOF AND SUPPORTING

THE SLOTTED PORTIONS OF THE GUN BARREL ALONG SUBSTANTIALLY EVERY PORTION OF THE CURVE THEREIN.

Description

Sept. 20, 1971 J. J. KRANZ 3,605,313

CHOKE MEANS Filed Feb. 6, 1969 VII/ 111117111 /z 2/ 20 FIG. 4 22 FIG. 6 25 IZ. 25 I kl g INVENTOR.

I JffEM/AH J. KRANZ L 7 fM 4 AT TORNE Y8 United States Patent 3,605,313 CHOKE MEANS Jeremiah J. Kranz, 3620 Jefferson St., Rapid City, S. Dak. 57701 Filed Feb. 6, 1969, Ser. No. 797,149 Int. Cl. F41c 21/18; F4lf 17/12 U.S. CI. 4279 4 Claims ABSTRACT OF THE DISCLOSURE A tubular member coaxially fitted over the muzzle and a slotted portion of a gun barrel in longitudinally sliding engagement therewith having an arcuately converging inner surface for forcing the slotted portions of the gun barrel inwardly to vary the choke thereof and supporting the slotted portions of the gun barrel along substantially every portion of the curve therein.

BACKGROUND OF THE INVENTION Field of the invention In the use of guns, such as shotguns and the like, it is often necessary to vary the choke or constriction of the muzzle to vary the shot pattern. It is especially desirable to be able to vary the choke of the muzzle when the gun is used for several different purposes, such as hunting upland birds, small animals, ducks, trap and/ or skeet shooting, etc.

Description of the prior art Many variable choke attachments have been devised in the prior art which are useful to alter the constriction of the muzzle of a gun barrel. In the most prominent of these an open ended sleeve is provided with a tapered bore along a portion thereof, which taper extends in an even or straight line from the forward end of the sleeve to a mid-section thereof. Because the taper is angularly disposed with respect to the remainder of the sleeve and the outer diameter of the gun barrel, the sleeve does not support the gun barrel along the length of the sleeve during the use thereof. That is, only the muzzle of the gun barrel engages the tapered portion of the sleeve and portions of the gun barrel to the rear of the muzzle are unsupported by the sleeve. These unsupported portions of the gun barrel receive the initial shock of the shot passing through the barrel and, because they are unsupported, have a tendency to break after a relatively short period of usage, or develop a permanent constriction.

SUMMARY OF THE INVENTION The present invention pertains to improved choke means including a tubular member having an arcuately converging inner surface for slidably engaging the muzzle and a slotted portion at the end of a gun barrel and supporting the entire constricted portion of the gun barrel.

It is an object of the present invention to provide a new and improved choke means for a gun barrel.

It is a further object of the present invention to provide choke means having an arcuately converging inner surface for constricting a slotted portion of a gun barrel and supporting the gun barrel along the entire constricted portion thereof.

These and other objects of this invention will become apparent to those skilled in the art upon consideration of the accompanying specification, claims and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Referring to the drawings, wherein like characters indicate like parts throughout the figures:

Patented Sept. 20, 1971 FIG. 1 is a view in side elevation of a portion of a shotgun having the present choke means installed thereon;

FIG. 2 is a view in bottom plan of the gun and choke means illustrated in FIG. 1;

FIG. 3 is an enlarged view as seen generally from the line 3-3 in FIG. 2, partially in elevation and partially in section, with portions thereof broken away;

FIG. 4 is an enlarged sectional view similar to a portion of FIG. 3, illustrating another position;

FIG. 5 is an end elevational view as seen from right to left of FIG. 4;

FIG. 6 is an enlarged sectional view as seen from the line 66 in FIG. 1; and

FIG. 7 is a sectional view as seen from the line 7-7 in FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENT The numeral 10 generally designates a shotgun having a barrel 11 with an elongated tubular magazine 12 thereunder. The barrel 11 has a plurality of circumferentially spaced apart slots 13 extending from the end or muzzle 14 of the barrel 11 longitudinally rearwardly a predetermined distance. The length of the slots 13 and the width thereof are determined by the maximum choke desired and are generally sufiicient so that the muzzle 14 can be urged inwardly to the desired constricting position and the slotted portion of the barrel 11 will converge in a smooth arc.

The barrel 11 has a tubular member 20 slidably engaged thereover so that a portion of the tubular member 20 overlies the slots 13 and the muzzle 14. The tubular member 20 has an inner diameter slightly larger than the outer diameter of the barrel 11 at a first end thereof designated 21. The inner diameter of the tubular member 20 remains constant for a substantial length thereof so that the tubular member 20 can be engaged over the barrel 11 Without providing any choking action thereto. The remainder of the surface, designated 22, of the inner wall of the tubular member 20 converges inwardly toward the opposite end thereof in a smooth arcuate curve. The inner diameter of the tubular member 20 adjacent the forwardmost end is sufficient to urge the slotted portion of the barrel 11 into the maximum desired choke or constricted portion, as illustrated in FIG. 4.

The surface 22 of the inner wall of the tubular member 20 is formed so that it diverges arcuately, in a generally concave configuration, from the forwardmost end of the tubular member 20 toward the first end 21 for a distance approximately equal to the length of the slots 13. When the diameter of the arcuately diverging surface 22 is equal to the inner diameter of the tubular member 20 adjacent the first end 21, the straight surface and the diverging surface blend smoothly together to form a continuous, smooth surface. The curve of the arcuate surface 22 is formed substantially similar to the curve of the slotted portion of the barrel 11 when the muzzle 14 is urged into a desired choked or constricted position. Thus, as the tubular member 20 is moved into positions of greater overlying engagement with the barrel 11 and the muzzle 14 is urged into more constricting positions, the slotted portion of the barrel 11 follows the curve of the arcuate surface 22 in the tubular member 20 so as to lie generally parallel and in juxtaposition to the surface of the inner wall of the tubular member 20 along the entire curved portion of the barrel 11. Normally, slotting and bending the end of the barrel 11 greatly weakens the barrel 11 and causes eventual breaking thereof. However, since the slotted portion of the barrel 11 is supported along its entire length by the tubular member 20 the tendency toward eventual breakage is greatly reduced, if not eliminated. Also, there is little or no tendency for the slotted portion to develop a permanent choke or constriction.

T-he forwardmost end of a connecting member 25 is afiixed to the under side of the tubular member 20 and the rear end thereof is bifurcated with a part or branch thereof extending for a short distance on both sides of and parallel with the magazine 12. A handle 26 is afiixed to the branches of the connecting member 25 so as to be slidably engaged over the magazine 12 adjacent the forward end thereof. In. the present disclosure the shotgun is a pump-action type having an action slide handle 27 slidably engaged over the magazine 12. The handle 26 must be engaged over the magazine 12 so as not to interfere with the operation of the action slide handle 27. In instances where the gun is a type having a stationary fore arm the handle 26 can be incorporated in the fore arm so as to form a portion thereof if desired while allowing the required amount of longitudinal movement. In the present embodiment six screws 28, three on either side, affix the handle 26 to the branches of the connecting member 25. A slot 29 is formed in the lower surface of the handle 26 and a stop member 30 is threadedly engaged in the magazine 12 so as to extend into the slot 29 and limit the longitudinal movement of the handle 26 and, consequently, the tubular member 20.

In the present shotgun 10 a ring 35 is affixed to the under side of the barrel 11 in a spaced apart relationship, by means of webbing 36 welded to the barrel 11. The ring 35 receives the forward end of the magazine 12 therein and aids in maintaining the magazine 12 in the desired position beneath the barrel 11. For purposes of forming a detent, to maintain the tubular member '20 at the desired longitudinal position, a hole 38 is formed transversely through the webbing 36. The hole 38 is somewhat diminished in diameter adjacent one end 39 thereof and is provided with internal threads adjacent the other end 40 thereof. A ball 41, spring 42 and screw 43 are engaged in the hole 38, in the order set forth, to form the detent. The diameter of the ball 41 is such that it extends outwardly from the one end 39 of the hole 38 but cannot pass completely therethrough. The inner surface of one of the branches of the connecting member 25 is dimpled at 45 (see FIG. 6) to receive the outwardly projecting portion of the ball 41 therein and provide the detent action. Thus, the detent action maintains the tubular member 20 in substantially any desired longitudinal position.

The illustrated and described embodiment is utilized for its simplicity and it should be understood that many modifications and improvements can be incorporated in the desired choke means. Further, the device can be incorporated in many different types of guns in which choking or constricting of the barrel is desirable. Also, the means for moving and holding the tubular member 20 in the desired position is only exemplary and many modifications and improvements can be incorporated therein.

Thus, an improved choke means is disclosed which greatly increases the life and efficiency of the choke and greatly decreases the possibility of permanently damaging the barrel of the gun on which it is installed.

What .is claimed is:

1. Improved choke means for a gun barrel having a plurality of circumferentially spaced, longitudinally extending slots formed therein adjacent the muzzle thereof, said choke means comprising:

(a) a tubular member having an inner diameter adjacent one end thereof slightly larger than the outer diameter of the gun barrel;

(b) a portion of said tubular member spaced longitudinally from said one end having an inner diameter a predetermined amount smaller than the outer diameter of the gun barrel;

(0) the inner wall of said tubular member having a longitudinally extending arcuately diverging concave surface extending from said portion toward said one end; and

(d) said tubular member slidably engaging the gun barrel in an at least partially overlying relationship with said portion extending beyond the muzzle in a substantially unconstricting position, and said arcuate surface urging the muzzle and slotted portion of the gun barrel radially inwardly in a substantially continuous arcuate curve and providing support for the gun barrel along substantially the entire curve in a constricting position, the predetermined smaller diameter of said portion of said tubular member being sufiicient to urge the muzzle of the gun :barrel into a position to provide the desired choking action.

2. Improved choke means as set forth in claim 1 including means attached to the tubular member for moving said tubular member between the constricting and unconstricting positions and for maintaining said tubular member in the desired one of said positions.

3. Improved choke means as set forth in claim 1 wherein the arcuate surface extends longitudinally Within the tubular member a distance approximately equal to the length of the longitudinal slots in the gun barrel.

4. Improved choke means as set forth in claim 1 including means for providing the tubular member with a plurality of positions relative to the gun barrel so as to render the choke means variable.

References Cited UNITED STATES PATENTS 653,613 7/ 1900 Broyles 42-79 1,348,750 8/ '1 920 Sohuster 42-79 1,508,605 9/1924 'Legett et al 4279 2,442,899 6/ 1948 McAllister 42-79 BENJAMIN A. BOROI-IELT, Primary Examiner C. T. JORDAN, Assistant Examiner